I select a classification metadata linked to LDAP uid attribute, for my directory root page.
People which have a uid with only numbers such as "20400614", are not in virtual page tree.

Proposed solutions :

1. Support this. Why we can not apply the same solution done for transitional page: prefix it by "page-" if the name is a number.
2. Or, if it is a limitation, inform the user :
   1. Log in warn that the page of user cannot be generated
   2. and display an warn message in dialog box setting the user directory root page: "Warning ! Make sure to select a classification metadata which value contains at least one alphabetic character. Contents for which the value does not contain an alphabetic character will be ignored in the tree."